Display screen enable signal wake-up and battery voltage detection combination circuit

Abstract

The utility model discloses a display screen enable signal wakes up and detects battery voltage combined circuit, including through receiving single -end input's enable wake -up signal to realize the circuit assembly of double -end output, and double -end output includes enable wake -up signal output end and battery voltage detection signal output end, the circuit assembly includes triode Q1, triode Q2, resistance R3, resistance R4, resistance R8, resistance R9, resistance R10, electric capacity C3 and electric capacity C4, the utility model has the following advantages and effect can integrate two sub -circuit, and simplify into a circuit under the premise that can realize normal enable signal wake -up function and battery voltage detection, reduce circuit complexity and reduce cost.

Description

Technical Field

[0001] This utility model relates to the field of automotive electronic circuits, and in particular to a circuit that combines display screen enable signal wake-up and battery voltage detection. Background Technology

[0002] With the increasing intelligence and integration of automobiles, there are higher requirements for the security and simplification of in-vehicle display systems.

[0003] Since the display screen's illumination needs to be controlled based on the actual conditions of the vehicle, an enable signal wake-up circuit is required. Simultaneously, the vehicle display system needs to assess the input battery power to ensure that specific modules can be shut down in case of power system instability, preventing system errors caused by power instability.

[0004] In existing technologies, to achieve the above functions, two independent sub-circuits are configured, with the two sub-circuits used to output an enable wake-up signal and a battery voltage detection signal, respectively; specifically:

[0005] As attached Figure 1 As shown, through the Enable (enable wake-up signal), resistor R34 is used to limit the current to protect the dual transistor Q1 when it is turned on. When the dual transistor Q1 is turned on, the voltage at pin 3 of the dual transistor Q1 is basically the same as VPP. Resistor R33 is a pull-down resistor to stabilize the LDO_EN state, keeping it at a low level when the Enable state is unstable. Resistor R32 is a current-limiting resistor to protect the MCU from being burned out, while capacitor C19 acts as a filter to make the LDO_EN signal more stable. The presence of voltage in LDO_EN is used to determine whether Enable has a level, thus realizing the enable signal wake-up function. At the same time, in order to ensure the power-down sequence, when Enable is powered down, the MCU HOLD ON will maintain the LDO_EN level. Resistor R6 acts as a current limiter when maintaining the level, and diode D7 prevents the reverse voltage from affecting the MCU when the MCU HOLD ON is low and the dual transistor Q1 is turned on.

[0006] As attached Figure 2 As shown, the dual transistor Q14 is turned on by ADC_EN. When the dual transistor Q14 is on, resistor R216 limits the current to protect it. When the dual transistor Q14 is on, the voltage at pin 3 of Q14 is basically the same as VBATT. After voltage division by resistors R217 and R218, the ADC signal is output. Capacitor C345 acts as a filter to make the ADC signal more stable. Finally, the voltage of VBATT is determined by judging the voltage of the ADC, thus realizing the function of detecting the battery voltage.

[0007] The existing technology uses two separate sub-circuits, which not only increases circuit complexity but also raises the cost of electronic components. If the two sub-circuits could be integrated and simplified into a single circuit while still achieving normal enable signal wake-up and battery voltage detection, the complexity and cost would undoubtedly be reduced. Utility Model Content

[0008] The purpose of this invention is to provide a circuit that combines a display screen enable signal wake-up and battery voltage detection to solve the problems mentioned in the background art.

[0009] The above-mentioned technical objective of this utility model is achieved through the following technical solution: a display screen enable signal wake-up and battery voltage detection combined circuit, including a circuit assembly that realizes dual-ended output by receiving a single-ended input enable wake-up signal; wherein, the dual-ended output includes an enable wake-up signal output terminal and a battery voltage detection signal output terminal;

[0010] The circuit assembly includes transistor Q1, transistor Q2, resistors R3, R4, R8, R9, R10, capacitor C3, and capacitor C4.

[0011] The base of transistor Q1 is used to receive a single-ended input enable / wake-up signal, the emitter is grounded, and the collector is connected to one end of resistor R3. The other end of resistor R3 is connected to the base of transistor Q2 and one end of resistor R4. The other end of resistor R4 is connected to the emitter of transistor Q2, and this end is also connected to the battery power supply. The collector of transistor Q2 is connected to the enable / wake-up signal output terminal, and a capacitor C3 is connected in series between the enable / wake-up signal output terminal and ground.

[0012] The collector of transistor Q2 is also connected to one end of resistor R8. The other end of resistor R8 is connected to one end of resistor R9 and one end of resistor R10. The other end of resistor R9 is grounded, and the other end of resistor R10 is connected to the battery voltage detection signal output terminal. A capacitor C4 is connected in series between the battery voltage detection signal output terminal and ground.

[0013] A further provision is that the circuit assembly also includes resistors R5, R6, and R7, and an enable control terminal capable of generating high / low levels;

[0014] The resistor R5 is connected in series between the collector of transistor Q2 and the enable / wake-up signal output terminal, the resistor R7 is connected in series between the enable / wake-up signal output terminal and ground, and the resistor R6 is connected in series between the enable control terminal and the enable / wake-up signal output terminal.

[0015] A further provision is that the circuit assembly also includes diodes D1 and D2 for reverse connection protection;

[0016] The diode D1 is connected in series between the collector of transistor Q2 and resistor R5, and the anode of diode D1 is connected to the collector of transistor Q2; the diode D2 is connected in series between resistor R6 and the enable / wake-up signal output terminal, and the anode of diode D2 is only connected to resistor R6.

[0017] A further provision is that the circuit assembly also includes resistors R1 and R2, capacitors C1 and C2;

[0018] One end of resistor R1 is connected to one end of capacitor C1, which is also connected to the single-ended input enable / wake-up signal. The other end of resistor R1 is connected to the base of transistor Q1 and one end of resistor R2, and the other end of resistor R2 is grounded. The other end of capacitor C1 is connected to one end of capacitor C2, and the other end of capacitor C2 is grounded.

[0019] This utility model has the following beneficial effects:

[0020] 1. High integration and reduced cost: Through innovative circuit design, the originally separate enable signal wake-up circuit and battery voltage detection circuit are integrated into a single circuit assembly; directly reducing redundant components, significantly reducing the number of electronic components used, and lowering costs.

[0021] 2. Simplified circuit complexity: The single-ended input enable wake-up signal drives the dual-ended output simultaneously to determine whether the battery voltage detection and signal wake-up functions are implemented; eliminating two sets of independent control logic; the design is simpler and the wiring is more compact. Attached Figure Description

[0022] Figure 1 A circuit diagram for a scheme that outputs an enable wake-up signal in the prior art;

[0023] Figure 2 This is a circuit diagram of a solution for outputting a battery voltage detection signal in the prior art;

[0024] Figure 3 This is the circuit diagram for this application. Detailed Implementation

[0025] The present invention will be further described in detail below with reference to the accompanying drawings.

[0026] As attached Figure 3 As shown;

[0027] This embodiment discloses a circuit combining a display screen enable signal wake-up and battery voltage detection, including a circuit assembly that achieves dual-ended output by receiving a single-ended input enable wake-up signal; wherein, the dual-ended output includes an enable wake-up signal output terminal and a battery voltage detection signal output terminal;

[0028] Specifically, in the appendix Figure 3 In the diagram, the single-ended input enable / wake-up signal corresponds to Host_Enable; the enable / wake-up signal output corresponds to MCU_LDO_EN; the battery voltage detection signal output corresponds to Host_Enable_ADC; the battery power supply corresponds to VPP; and the enable control terminal corresponds to MCU_Hold_ON.

[0029] The circuit assembly includes transistors Q1 and Q2, resistors R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, capacitors C1, C2, C3, and C4, and diodes D1 and D2.

[0030] One end of resistor R1 is connected to one end of capacitor C1, which is also connected to the single-ended input wake-up signal Host_Enable. The other end of resistor R1 is connected to the base of transistor Q1 and one end of resistor R2, with the other end of resistor R2 grounded. The other end of capacitor C1 is connected to one end of capacitor C2, with the other end of capacitor C2 grounded. The emitter of transistor Q1 is grounded, and the collector is connected to one end of resistor R3. The other end of resistor R3 is connected to the base of transistor Q2 and one end of resistor R4, with the other end of resistor R4 connected to the emitter of transistor Q2, which is also connected to the battery power supply VPP.

[0031] The collector of transistor Q2 is connected to the positive terminal of diode D1 and one end of resistor R8. The other end of resistor R8 is connected to one end of resistor R9 and one end of resistor R10. The other end of resistor R9 is grounded. The other end of resistor R10 is connected to one end of capacitor C4, which is also connected to the battery voltage detection signal output terminal Host_Enable_ADC. The other end of capacitor C4 is grounded.

[0032] The cathode of diode D1 is connected to one end of resistor R5, the other end of resistor R5 is connected to the cathode of diode D2, one end of resistor R7 and one end of capacitor C3, and this end is also connected to the enable wake-up signal output terminal MCU_LDO_EN; the other ends of resistor R7 and capacitor C3 are both grounded, the anode of diode D2 is connected to one end of resistor R6, and the other end of resistor R6 is connected to the enable control terminal MCU_Hold_ON that can generate high / low levels.

[0033] A further optimization involves connecting a transient voltage suppressor (TVS2) in series between the single-ended input enable / wake-up signal Host_Enable and ground, providing surge protection.

[0034] The working principle of this embodiment is as follows:

[0035] The single-ended input enable / wake-up signal Host_Enable, which functions as the wake-up signal during implementation, controls the conduction of transistors Q1 and Q2. When Host_Enable is high, transistor Q1 is turned on after filtering by capacitors C1 and C2 and current limiting by resistor R1 (resistor R2 is a pull-down resistor, stabilizing transistor Q1 when Host_Enable is not high). When transistor Q1 is on, Ube of transistor Q2 is greater than 0.7V, causing Q2 to conduct. Resistors R3 and R4 provide current limiting protection. At this point, the collector voltage of transistor Q2 is approximately equal to the battery power supply VPP. Through voltage division by resistors R8 and R9 and filtering by capacitors C3 and C4, the output terminals Host_Enable_ADC (battery voltage detection signal) and MCU_LDO_EN (enable wake-up signal) are used to determine the power supply voltage and the presence of the enable wake-up signal, respectively, to achieve the functions of detecting battery voltage and waking up the circuit. Resistors R5 and R6 are used for current limiting to protect the circuit. Diodes D1 and D2 provide reverse connection protection, and resistor R7 is a pull-down resistor used to stabilize the state of the MCU_LDO_EN enable wake-up signal output terminal when the single-ended input enable wake-up signal Host_Enable is not pulled high.

[0036] This specific embodiment is merely an explanation of the present utility model and is not intended to limit the present utility model. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but as long as they are within the scope of the claims of the present utility model, they are protected by patent law.

Claims

1. A circuit combining display screen enable signal wake-up and battery voltage detection, characterized in that: It includes a circuit assembly that achieves dual-ended output by receiving an enable wake-up signal from a single-ended input; wherein the dual-ended output includes an enable wake-up signal output terminal and a battery voltage detection signal output terminal; The circuit assembly includes transistor Q1, transistor Q2, resistors R3, R4, R8, R9, R10, capacitor C3, and capacitor C4. The base of transistor Q1 is used to receive a single-ended input enable / wake-up signal, the emitter is grounded, and the collector is connected to one end of resistor R3. The other end of resistor R3 is connected to the base of transistor Q2 and one end of resistor R4. The other end of resistor R4 is connected to the emitter of transistor Q2, and this end is also connected to the battery power supply. The collector of transistor Q2 is connected to the enable / wake-up signal output terminal, and a capacitor C3 is connected in series between the enable / wake-up signal output terminal and ground. The collector of transistor Q2 is also connected to one end of resistor R8. The other end of resistor R8 is connected to one end of resistor R9 and one end of resistor R10. The other end of resistor R9 is grounded, and the other end of resistor R10 is connected to the battery voltage detection signal output terminal. A capacitor C4 is connected in series between the battery voltage detection signal output terminal and ground.

2. The display screen enable signal wake-up and battery voltage detection combined circuit according to claim 1, characterized in that: The circuit assembly also includes resistors R5, R6, and R7, and an enable control terminal that can generate high / low levels; The resistor R5 is connected in series between the collector of transistor Q2 and the enable / wake-up signal output terminal, the resistor R7 is connected in series between the enable / wake-up signal output terminal and ground, and the resistor R6 is connected in series between the enable control terminal and the enable / wake-up signal output terminal.

3. The display screen enable signal wake-up and battery voltage detection combined circuit according to claim 2, characterized in that: The circuit assembly also includes diodes D1 and D2 for reverse connection protection; The diode D1 is connected in series between the collector of transistor Q2 and resistor R5, and the anode of diode D1 is connected to the collector of transistor Q2; the diode D2 is connected in series between resistor R6 and the enable / wake-up signal output terminal, and the anode of diode D2 is only connected to resistor R6.

4. The display screen enable signal wake-up and battery voltage detection combined circuit according to claim 1, characterized in that: The circuit assembly also includes resistor R1, resistor R2, capacitor C1, and capacitor C2; One end of resistor R1 is connected to one end of capacitor C1, which is also connected to the single-ended input enable / wake-up signal. The other end of resistor R1 is connected to the base of transistor Q1 and one end of resistor R2, and the other end of resistor R2 is grounded. The other end of capacitor C1 is connected to one end of capacitor C2, and the other end of capacitor C2 is grounded.

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